refactor

src/ui.rs

@@ -0,0 +1,84 @@
+use std::io::stdout;
+use std::io::Write;
+
+use anyhow::{bail, Result};
+use crossterm::{
+    cursor::{self, MoveTo},
+    event::{Event, EventStream, KeyCode, KeyModifiers},
+    terminal::{self, disable_raw_mode, enable_raw_mode},
+    ExecutableCommand, QueueableCommand,
+};
+use futures::StreamExt;
+use tokio::sync::broadcast::Sender;
+
+use crate::message::Message;
+
+pub(crate) struct Ui {
+    sender: Sender<Message>,
+}
+
+impl Ui {
+    pub(crate) fn new(sender: Sender<Message>) -> Self {
+        Self { sender }
+    }
+
+    pub(crate) async fn main_loop(self) -> Result<()> {
+        let mut reader = EventStream::new();
+
+        loop {
+            enable_raw_mode()?;
+            stdout().execute(cursor::Hide)?;
+
+            if let Some(Ok(Event::Key(key_event))) = reader.next().await {
+                let should_exit = self.handle_key_event(key_event)?;
+                if should_exit {
+                    return Ok(());
+                };
+            }
+        }
+    }
+
+    fn handle_key_event(&self, key_event: crossterm::event::KeyEvent) -> Result<bool> {
+        if Self::is_char_q(key_event) {
+            self.prepare_for_program_quit()?;
+            return Ok(true);
+        };
+        if Self::is_ctrl_c(key_event) {
+            self.prepare_for_program_quit()?;
+            self.sender.send(Message::CtrlC)?;
+            bail!("<Ctrl-C>");
+        }
+        if Self::is_space(key_event) {
+            self.sender.send(Message::TogglePause)?;
+        }
+        Ok(false)
+    }
+
+    fn prepare_for_program_quit(&self) -> Result<()> {
+        self.sender.send(Message::Quit)?;
+        disable_raw_mode()?;
+        stdout().execute(cursor::Show)?;
+        Ok(())
+    }
+
+    fn is_char_q(key_event: crossterm::event::KeyEvent) -> bool {
+        key_event.code == KeyCode::Char('q')
+    }
+
+    fn is_space(key_event: crossterm::event::KeyEvent) -> bool {
+        key_event.code == KeyCode::Char(' ')
+    }
+
+    fn is_ctrl_c(key_event: crossterm::event::KeyEvent) -> bool {
+        key_event.code == KeyCode::Char('c') && key_event.modifiers.contains(KeyModifiers::CONTROL)
+    }
+}
+
+pub(crate) fn clear_terminal() -> Result<()> {
+    let mut stdout = stdout();
+    stdout.queue(terminal::Clear(terminal::ClearType::All))?;
+    stdout.queue(terminal::Clear(terminal::ClearType::Purge))?;
+    stdout.queue(MoveTo(0, 0))?;
+    stdout.flush()?;
+    Ok(())
+}